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Neurology India, Vol. 59, No. 5, September-October, 2011, pp. 685-689 Original Article The efficacy of transforaminal epidural steroid injections in lumbosacral radiculopathy Chinmoy Roy1, Nilay Chatterjee1, Satya Narayan Patro2, Amit Chakraborty3, GR Vijay Kumar3, Robin Sengupta3 1 Department of Pain Management, Institute of Neurosciences, Kolkata, West Bengal, India PMID: 22019651 DOI: 10.4103/0028-3886.86541 Objective: To evaluate long-term efficacy of TFES in patients with lumbosacral radiculopathy. Materials and Methods: A prospective study including 30 patients having lumbosacral radiculopathy secondary to prolapsed disc. Outcome variables were the amount of improvement just after the procedure and thereafter at 24 hrs, 1 month, 6 month and 1 year post-procedure, respectively, using visual analog scale (VAS) and numeric rating scale (NRS). Patients also filled Roland-Morris questionnaire pre-procedure, 6 month and 1 year follow-up. All patients received Ibuprofen for 3 days following the procedure, to alleviate post- procedural pain. An option of rescue surgery was reserved in case of unbearable pain (>7 VAS), appearance of sudden motor deficit or if patient opts for surgery. Same injection was repeated if at any point of time pain had >5 in VAS. Results: As per NRS, almost all patients had complete pain relief (mean 98%) immediate postprocedure. At 24 hrs, the score was 79%, at 1 month 60%, at 6 months 58.5% and at 1 year 59%. Preprocedure VAS was 9.2 and thereafter 0.6, 1.8, 3.9, 3.8 and 4.2 at similar time points. Roland-Morris score was 18/24, 10/24, 9/24, at pre-procedure, at 6 months and at 1 year, respectively. No complication was noted in any patient except post procedural local pain. Conclusion: Quality of pain relief produced by TFES was significant. Long-term quality of pain relief was better in patients with pain duration less than 6 months. Even though, the study was designed to inject the drug once, many of the patients required second injection. A further study with multiple injections at prefixed time interval might probably result in a better overall outcome. Keywords: Lumbosacral radiculopathy, radiculitis, transforaminal epidural steroid Introduction Sciatica is the term generally used for lumbosacral radiculopathy, [1] which is commonly caused by disc herniation, although a space occupying lesion in the lumbosacral spine or spondylolisthesis can also result in such clinical condition. About 10-15% of patients with lumbosacral radiculopathy eventually require surgery [2],[3] but overall the majority recover with conservative management. [4],[5],[6] Studies suggest inflammation of the affected nerve roots in the mechanism of pain. [7],[8],[9] The inflammatory component has attracted the use of corticosteroids to decrease inflammation and thus reduction in pain. Steroid injections have been used through different routes as an alternative to surgery or adjunct to conservative therapy. Epidural steroid injection has been used for treatment of lumbosacral radiculopathy, [10],[11] with varying success rates, 20- 80% [12],[13] and efficacy lasting for an average period of not more than 3 months. These divergent results are because of various methodological and technical limitations in the studies. [14],[11] Epidural injections when performed through translaminar or caudal approaches without fluoroscopy and contrast are likely to miss the perceived target area in 30-40% instances. [15] Moreover, it remains questionable whether an adequate concentration of the corticosteroid could be delivered to the target tissues by such approaches, irrespective of the use of fluoroscope. [10] The transforaminal epidural steroid injection (TFES), using fluoroscopy and contrast permits a high concentration of corticosteroid at the target site, which is the ventral aspect of the lumbar root sleeve and the dorsal aspect of herniated disc. [16] Recent studies have supported the efficacy of TFES for prolapsed disc. [17] However, till date very few studies have demonstrated the long-term outcome and efficacy of TFES in lumbosacral radiculopathy due to herniation of nucleus pulposus (HNP) in an objective manner. We present a study of TFES in 30 patients and evaluate the efficacy with respect to time and also the quality of analgesia. Materials and Methods This is a prospective pilot study of 30 patients presenting to a tertiary care neurosciences center with lumbosacral radiculopathy secondary to prolapsed disc, as demonstrated by magnetic resonance imaging (MRI). The study has the approval of the Institutional Ethical Committee. Inclusion criteria included: 1) adult patients capable of giving informed consent after understanding the treatment options available, and capable of complying with the outcome measures used in the study; 2) patients primarily having leg pain greater than back pain and a typical dermatomal pattern associated with limitation of straight-leg-raise to less than 45 degree, and with prolapsed intervertebral disc (PIVD) confirmed by MRI; and 3) all patients have undergone conservative treatment for at least 4 weeks. All patients were referred by the neurosurgeon and were newly diagnosed cases eligible for surgery. Patients opted voluntarily for nonsurgical alternatives after being explained the management options, and surgery would be the next intervention if TFES injection fails. Patients were excluded if they had motor deficit, previous back surgery, history of substance abuse, signs of infection, coagulopathy, history of allergy to local anesthetic or any drug, osteophytes, extruded or migrated disc, spondylolisthesis or severe spinal deformity and inability to comply with the measures of outcome analysis. All the injections were performed by the lead author under fluoroscopic guidance while the patient was lying in prone position [Figure - 1]. The nerve root to be infiltrated was determined by the referring surgeon and the interventional pain physician together after consultation. Typically S1 nerve root was located in S1 dorsal foramen, L5 nerve root in L5- S1 intervertebral foramina, L4 in L4-L5 foramina and so on. Multilevel injections were given in many patients depending on the diagnosis. TFES injection was delivered through the 'safe triangle' [Figure - 2] which comprised of a roof made by the pedicle of vertebra, a tangential base corresponding to the exiting nerve root and the lateral border of the vertebral body. Fluoroscopy was started with anterior-posterior view and then mild craniocaudal tilt was applied to view the upper end plate of the lower vertebra as a single line. Next step was to give 10-20 degree oblique tilt to place the needle under the pedicle using the tunnel view. Lateral X-ray confirmed the position of the needle at the ventral aspect of the foramen. At each level 1-2 ml of contrast medium iohexol (omnipaque 300) was injected to outline the nerve root [Figure - 3] and [Figure - 4]. Epidural spread was also expected with 2 ml of contrast. Drug was never injected in case of any doubt regarding the pattern of spread of the contrast. Methylprednisolone acetate (Depomedrol 0.5 ml/20 mg) and preservative free 0.5% bupivacaine (1.5 ml/7. 5 mg) were injected together in a single syringe per nerve root. Altogether 33 patients, intended to be followed-up for a period of 1 year, were included in this study. Three patients were lost for follow-up and the final analysis included 30 patients. Patients had received an average of 1.3 TFES injections (range 1-2 TFES) at the very first session. Nine patients required repetition of same injections at an average time interval of 4.2 months. All patients had received Ibupropofen for first 3 post-procedure days to alleviate procedural pain. Subsequent to the procedure, all patients were directed to consult same physiotherapist for back-strengthening exercises, starting after day-7 of the procedure. Treatment outcomes were measured by visual analog scale (VAS), numeric rating scale (NRS), and Roland-Morris low back pain and disability questionnaire. For measuring VAS a standard 10 cm scale was used where 0 corresponded to 'no pain' and 10 to 'worst pain' patient had ever perceived. A NRS (101 point) with options ranging from 0 (no pain) to 100 (worst pain experienced in the last 1 week) was used. Roland-Morris questionnaire was filled by the patient thrice, preprocedure, after 6 months and after 1 year. VAS and NRS outcome measures were collected just after the procedure, after 24 hrs, at 1 month, 6 month and at 1 year. All results were recorded by an independent investigator who was not involved in the interventional procedures. A successful outcome of the treatment was defined as improvement of at least 60% after 12 months of the procedure. All results were expressed in mean ± SD. For VAS and Roland-Morris scores preprocedure and postprocedure values at different time points were compared with ANOVA test. SPSS (version 17.0) was used for analysis. Results As per NRS, almost all patients had complete pain relief (overall 98%, with 100% in 28 and 80% in 2 patients) immediate after the procedure. After 24 hrs, average pain relief was 79%, after 1 month 60%, after 6 months 58.5% and after 1 year it remained at 59%. VAS was 9.2 (preprocedure) and thereafter 0.6, 1.8, 3.9, 3.8 and 4.2, respectively, at similar time points. Roland-Morris score was 18/24, 10/24, 9/24, at preprocedure, at 6 months and at 1 year, respectively. No complication occurred in any of our patients, but post procedural local pain was experienced by all the patients. No one required or opted for rescue surgery but TFES injection had to be repeated in nine patients at different time intervals (average 4.2 months) [Table - 1] and [Table - 2]. Discussion The rationale for using epidural steroids originates from the studies showing abnormal concentrations of nociceptive and inflammatory mediators, around lumbosacral disc herniations causing a chemical neuroradiculitis. [18],[19] Corticosteroids, by inhibiting prostaglandin synthesis, limit both cell-mediated and humoral immune responses. These drugs also stabilize cellular membranes and blocks nociceptive C-fiber conduction. [20],[21],[22] Systemic search of the literature reveals the efficacy of lumbosacral epidural steroid injection for radicular pain ranging from 0 to 100% and usually lasting for less than 3 months. [12],[9] The possible explanations for the high rates of success with TFES include: 1) precise delivery of the steroid bupivacaine solution; 2) antinociceptive and membrane stabilisation properties of both the agents; 3) potent anti-inflammatory properties of the steroid; and 4) washout effects of the solution causing decreased levels of interleukin 1 (IL 1), tumor necrosis factor (TNF) and phospholipase-chief factors mediating inflammation. Patients in the present study showed significant amount of improvement at 1 year with TFES. Maximum pain relief was immediately after the procedure which was obviously due to the local anaesthetic effect. Selection of newly diagnosed nonoperated cases with no spinal deformity, drug delivery after typical dye spread coupled with additional rehabilitation with graded exercises may explain the relative longer duration of pain relief with lesser injections in our patients. Older techniques/interventions for lumbosacral radiculopathy e.g., trigger point injections and lumbar/caudal epidural steroid injections are far less effective compared to TFES. These procedures require more volume of injectate as they get distributed over the entire epidural space and not delivered or confined to the exact site of pathology, thus reducing the potential therapeutic effects of corticosteroids needed to treat chemical radiculitis. The use of fluoroscopically guided TFES allows precise delivery of the medication reliably to the interface between HNP and the ventral aspect of the irritated nerve root. [10] The absence of complications like dural puncture and excessive bleeding that usually complicate blind epidural injections confirms the safety of fluoroscopically guided TFES approach. Factor associated with reduced success include the duration of symptoms for more than 6 months. It is strongly supported by the fact that all the patients requiring second session belonged to this category. Average time for reinjection was 4.2 months in our study, which has actually affected the results at 6 months and at 1 year, compared to pain relief at 1 month. Overall result at 1 year might have been influenced by the beneficial effects of exercise and physiotherapy. We have used three instruments to assess the outcomes. VAS showed postprocedure improvement rating as compared to preprocedure rating. NRS on the other hand compared the worst pain that was experienced by the patient in the last 7 days, this averaging was required, as a patient might have perceived lesser pain just prior to the procedure compared to other days.VAS recorded the pain present and NRS recorded the pain relieved. Again Roland-Morris low back pain and disability questionnaire provided the improvement in quality of life because of pain relief. In summary, this study showed TFES is a reliable method of providing statistically significant long term pain relief in patients having lumbosacral radiculopathy secondary to HNP. The results did not reach to the level of our expectation, as uniform 60% improvement was not achieved after 1 year interval (VAS-54.3%, NRS-59%, RM-49.4%). However, the long-term outcome trend is indeed encouraging. A further study with a greater number of patients and with multiple sessions of injections at prescheduled interval will confirm the beneficial effects of this mode of treatment. The limitations of the present study include a relatively small patient population, comparatively small follow-up period limited to 1 year, treatment protocol with a single injection and exclusion of all complicated patients. References
Copyright 2011 - Neurology India The following images related to this document are available:Photo images[ni11211t1.jpg] [ni11211f1.jpg] [ni11211t2.jpg] [ni11211f3.jpg] [ni11211f4.jpg] [ni11211f2.jpg] |
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